26 replies to this topic

[Struggler]

one tonna tail shaft length is diffrent and diameter is diffrent on one tonna's.... yoke size is same

Tonner pinion yokes are larger and take a different uni to any other Holden.

[yel327]

Hey guys, my work mate has just started a WB One-Tonna project... It currently has a Blue 202, and Trimatic.

He's just after a nice cruiser and not a ball tearer and wants to fit a Mild 308... my question is... Were the diffs the same in both the 6 and V8 1-tonnas? It does have a 10bolt diff... Im guessing the housings are the same just different ratio centers? so would it just be a matter of fitting a suitible center? Is it easy to get a LSD for these diffs? How much HP/Torque will these diffs handle?

Also are the brakes the same between the 6 and V8 models? if not whats different?

Tailshaft seems fairly beefy, so looks ok.... but are the V8's with a Trimatic or might be a T350/T700 are they all the same length/spline?

Will V8 engine mounts bolt straight onto the 6 crossmember or will he need to source a V8 crossmember?

And is there anything else you can think of that will need to be changed... Springs?

Thanks guys.... I know its not a Torana but is soo many knowlageable people on this forums. Cheers!

If it's originally a 202 trimatic it will be a 3.55 diff. Standard diff for a 253 trimatic is a 3.36 but plenty had 3.55. All 1-tonner diffs are identical. LSD's for these are identical to all HQ-WB V8, A9X and 308 VB-VK. They are getting hard to get though and 2.6/2.78 centre is also different. In all honesty if you want to have a taller LSD you'd be better off getting a 9" made up for it or getting a VN diff modified.
Note: 1-tonners use the same yoke and rear uni as all HQ 350 powered cars, and the uni is also identical to the front uni on all HQ-HZ with TH400. HG 350 also used the same uni.

All you need to put a 308 in it is:

A blue/black 308 and trimatic (just make sure you get one with the shift on the same side);
253/308 exhaust;
WB V8 auto radiator (or manual one with a separate txm cooler);
WB V8 throttle cable;
WB or VC-VK engine harness;
V8 trimatic dipstick.

Note that all tonners had heavy duty bits, regardless of whether they were 6cyl or V8. These were:

Heat treated front stubs (absent from very early HQ);
Bigger rear axles with wider bearing collars;
Big tailshaft;
1.125" front and rear unis;
Fully perimeter welded rims.

Different upper control arms and balljoints are also listed for WB tonners but i'm not sure what is different.
Front springs are different for 6cyl, but just buy some aftermarket V8 ones.
You'll also probably have to change the gear on the end of the speedo cable as V8 trimatics normally have a different gear inside.

[yel327]

v8 hq to wb tonnas run a different t/shaft diameter and rear uni to the sixes
but your diff should cope if not stressed
the v8's also run a claytons 12 bolt salsbury
the sixes run the commdore unit
sed/wagon/stato dont fit
you have to put the spring hangers on
all in all it's a easy job
done it all in a weekend

No they don't. All tonners (except TH350 and TH400) run the same tailshaft and diff yoke, plus the diffs are identical to all other Holden 10 bolts bar the tonners having bigger axles and bearing collars.

No 6cyl Holden runs a Commodore diff, except 6cyl WB ute and van run a baby salisbury (although I have been told some 253 WB utes and vans had baby diff but I've never seen one).

[Joshua]

No they don't. All tonners (except TH350 and TH400) run the same tailshaft and diff yoke, plus the diffs are identical to all other Holden 10 bolts bar the tonners having bigger axles and bearing collars.

No 6cyl Holden runs a Commodore diff, except 6cyl WB ute and van run a baby salisbury (although I have been told some 253 WB utes and vans had baby diff but I've never seen one).

one tonners come out with a small and large diff yoke.. and tailshaft to match

[yel327]

one tonners come out with a small and large diff yoke.. and tailshaft to match

No. All tonners have the same diff yoke with 1.125" uni regardless of engine and box (173 through to 308). Also have 1.125" front uni. Standard V8 (except HQ 350 which is same as tonner) has 1" uni front and rear except TH400 which has 1.125" front uni.

Yes 4.44 is often standard with 6cyl but also 3.55 was a very common option especially with auto 202. 3.55 was standard with V8 with 3.36 also common with L32/M40 and L31/M41.

[yel327]

dude the v8 diffs are heaps bigger and run bigger unis and t shaft diameter to the 6 sixes
seen it with my own two eyes
done the conversion heaps of times
remove a standard v8 10 bolt and compare them side by side
youll c what i mean

All tonners are the same, guarantee you as fact, surer than the sun will come up tomorrow. Where you are probably getting mixed up is HQ-WB utes and vans run different diffs 6cyl to V8 (HQ-HZ banjo with 6cyl, WB baby Salisbury with 6cyl, HQ-WB V8 10 bolt Salisbury). Tonner housing and centre is identical to normal 10 bolt, only yoke is machined for bigger uni (also same yoke as HQ 350) and axles are thicker with larger bearing collars. For further proof read any HQ-WB parts catalogue. The only difference between V8 and 6cyl tonner is 6cyl is standard with 4.44, V8 is standard with 3.55.

[yel327]

I should also qualify the above, early HQ parts catalogue is no good for tonner reference as tonner didn't appear till later plus 11/71 edition also not much good as V8 tonner wasn't available at that stage and 11/71 catalogue is full of misleading info regarding tonners.

Tonner also has to be a 10 bolt as you couldn't get a 4.44:1 in banjo or even baby salisbury (which didn't exist between 1971-1976 anyway).

[Joshua]

i'm still adamant they came out with small and large...
i've seen tonners with both... i've got 4 tonner diffs and i think it might be 2 and 2 small to large...

[yel327]

dude the thing is visual
had a v8 sdn and v8 tunna diff side by side
the tunna was nearly the size of a nine inch

They aren't different, I assure you. I've had dozens of tonners over the years right back to when they were new and the housing and centre casting are identical to a V8 sedan bar the mounts (leaf vs coil). They are even the same part number. Holden never used a bigger diff than the 10 bolt in HQ-WB in Australia, however they did use a 12 bolt Chev diff in some South African assembled HQ Statesman bodied vehicles.

[yel327]

not all 1`tonner diff's are the same although they look the same on the outside ie; you cant fit a 2.78 or a 3.36 into a 4.44 housing and vice versa and the axles on 1 tonners are bigger than a standard axle

That's not true either. All Salisbury housings for the same series Holden and Statesman (eg HJ) are the same except 60/70/80 have leaf spring mounts and 35/37/69 have coil mounts. Minor differences occured between series eg sway bar mounts for RTS on HZ and WB. You can fit gears from 2.6 through to 4.44 in the same housing, only the hemisphere is different (2.6 and 2.78 are interchangeable, 3.08, 3.36, 3.55, 3.90 and 4.44 are interchangeable). You are correct that tonners have bigger axles although when first released tonners were 6cyl only and it appears at that time they might have used normal V8 Salsibury axles unless there is an error in the parts catalogue released when HQ commercials were first available (11/71).

I've also always wondered why Harry Firth always talked about the A9X getting a shorter 1-tonner diff. Not sure why he said that, unless A9X got the tonner/350 diff yoke? A9X axles are same as HZ disc brake just shorter, they are nothing like a 1-tonner axle. It would have been more correct to say the diff is from the upcoming HZ V8 sedan range!

[yel327]

i'm still adamant they came out with small and large...
i've seen tonners with both... i've got 4 tonner diffs and i think it might be 2 and 2 small to large...

Josh, I missed this, this morning. What do you mean by small and large? Banjo and Salisbury? These two diffs were the only ones available until GMH re-packaged the banjo into a baby Salisbury for UC, WB 6cyl and VB-VH 4cyl, 6cyl and 253.